https://www.ludashi.com/commonV2/js/rollover.js

1/*
2	Standards Compliant Rollover Script
3	Author : Daniel Nolan
4	http://www.bleedingego.co.uk/webdev.php
5*/
6
7function initRollovers() {
8	if (!document.getElementById) return
9	
10	var aPreLoad = new Array();
11	var sTempSrc;
12	var aImages = document.getElementsByTagName('img');
13
14	for (var i = 0; i < aImages.length; i++) {		
15		if (aImages[i].className == 'imgover') {
16			var src = aImages[i].getAttribute('src');
17			var ftype = src.substring(src.lastIndexOf('.'), src.length);
18			var hsrc = src.replace(ftype, '_on'+ftype);
19
20			aImages[i].setAttribute('hsrc', hsrc);
21			
22			aPreLoad[i] = new Image();
23			aPreLoad[i].src = hsrc;
24			
25			aImages[i].onmouseover = function() {
26				sTempSrc = this.getAttribute('src');
27				this.setAttribute('src', this.getAttribute('hsrc'));
28			}	
29			
30			aImages[i].onmouseout = function() {
31				if (!sTempSrc) sTempSrc = this.getAttribute('src').replace('_o'+ftype, ftype);
32				this.setAttribute('src', sTempSrc);
33			}
34		}
35	}
36}
37
38window.onload = initRollovers;